This invention relates to dental apparatus, and in particular to syringe apparatus for providing a jet of air, liquid or air/liquid mixture to a patient undergoing dental treatment.
Such three-ay syringe apparatus is used for cleaning the mouth of dust and small particles of tooth or filling material after drilling, grinding, scraping or the like. The apparatus comprises a hand-held appliance to which a supply of air and a supply of water, both under pressure, are supplied, and has a nozzle assembly or nosel tip at the operating end thereof. Such nozzle assembly or nosel tip comprises a coaxial tube assembly which is secured on the end of the three-way syringe apparatus. Both inner and outer tube of the nosel tip are of metal, for example brass, stainless steel, anodised aluminum or the like, and since the inner tube must be supported within the outer tube whilst allowing flow through the outer tube, the nosel tip is relatively costly to produce. Although the three-way syringe apparatus is not actually intended to come into contact with the patient""s mouth, inevitably such contact does occur from time to time since the nosel tip must be placed within the mouth in order that the jet can be directed to the required location. Consequently it is possible for the nosel tip at least to become contaminated during use. Conventionally, the dentist of the dental assistant will clean the nosel tip, after use of the syringe device, by means of cleaning fluid. However, this is not a wholly satisfactory method of ensuring that the nosel tip is contamination-free for the next use. Alternatively, the nosel tip could be removed and autoclaved, but this is a time-consuming operation which is frequently not carried out.
It is an object of the present invention to provide a dental apparatus of the above described type whereby it is possible to ensure that a contamination-free apparatus is available for each occasion of use.
The invention provides a dental apparatus comprising a nosel tip for a three-way syringe device, the nosel tip comprising a co-axial tube assembly having attachment means adapted for releasable attachment of the nosel tip to a syringe device, wherein at least an outer tube of said co-axial tube assembly is of a plastics material.
By means of the invention the nosel tip can be cheaply produced so that each nosel tip may be removed from the syringe device after use on one patient and discarded, so that a new uncontaminated nossel tip can be attached to the syringe device for use on the next patient. In this way, the risk of cross-infection between patients is avoided or at least substantially reduced.
An inner tube of said coaxial tube assembly may be of metal, for example brass, stainless steel or anodised aluminum. Alternatively the inner tube may also be of a plastics material. The outer tube may be moulded onto the inner tube. The nosel tip may have a cap part which may be secured to or integral with said outer tube and said cap part may have the attachment means formed thereon. Said attachment means may comprise a screw-thread provided internally of the cap part or may comprise bayonet or catch receiving means. The apparatus may also comprise an adaptor, disposed between said nosel tip and syringe device, the adaptor allowing attachment of said nosel tip to the device. Thus in the case where an adaptor is present, it is possible for the same nosel tip to be fitted to different syringe devices by the use of different adaptors, said adaptor may have a cap part with a screw-thread attachment means provided internally thereof, and a screw-thread for engagement with the nosel tip or a bayonet or catch means adapted to be received in bayonet or catch receiving means on the nosel tip.
The adaptor may be arranged to cooperate with the nosel tip via securing means, the securing means providing a leak-proof connection between the nosel tip and adaptor. Preferably the adaptor has a recess therein in which one end of said securing means locates. In this case a seal may be provided to secure and seal the end of said securing means in the recess. The seal may be an xe2x80x98Oxe2x80x99 ring or rubber seal or the like. The other end of said securing means may have a plurality of flanges extending radially outward thereof, the flanges locating in grooves provided in said nosel tip. Preferably there are four such flanges spaced angularly by 90xc2x0 around the outer surface of said other end of the securing means.